The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.
A second screen device (also known as a “companion device”) may be a portable screen-based computing device (for example a smartphone, tablet computer) that allows a content consumer to interact with content (for example shows, movies, music, video games) that is presented by a media device (for example game console, set-top box, digital video player, television). In many cases, the second screen device is synchronized with the content displayed on the media device and displays additional options or data that enhances the user's experience. In typical cases, the second screen device and the media device are located close to each other (for example close enough that the user can view both screens without too much effort) and communicatively coupled over the user's local area network (LAN). As one example, a smartphone can be configured to allow a user to view live tweets or comments related to a program being displayed on their television. As another example, a tablet computer can be synchronized with a game console to display additional data, such as a map or heads-up display. As yet another example, a second screen device can be synchronized with a digital video recorder to select and control media for presentation, essentially replacing the need for a standard remote control.
However, while second screen technology allows multiple devices to work in concert to enhance the user's experience, many uses of this technology also require communication between the pairing and external servers on which the user has an account (for example servers that provide the media content, game servers that allow players to interact online). Thus, to protect the user's communications and devices, security is needed not only between the pair of devices, but also between the devices and the authentication server that binds the pairing to the user's account. This issue can also be made difficult in light of the fact that second screen devices may be more vulnerable to attack than the multimedia devices, as well as the converse. As a result, security for the system may run into Byzantine device failures (untrustworthy devices), as well as other standard attacks such as man-in-the-middle and replay.